JPH10338760A - Whole surface treatment for non-conductive porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of treating the whole-surface of non-conductive porous substance that can be carried out under atmospheric pressure, scarcely causes damage to the treated substrate and their uneven treatment by the spark discharge to enable continuous treatment and can achieve the surface modification with excellent durability. SOLUTION: A non-conductive porous body 11 supporting a surface treatment auxiliary agent on the face to be treated is arranged between a pair of electrodes 21, 22 both of which are arranged to oppose to each other and have dielectric layers 41, 42 on their opposing faces so that the porous body does not directly contact with the electrodes but their outer surfaces directly contact with the dielectric layers. Then, a low frequency alternative current voltage of 0.1-100 kHz frequency is applied between both electrodes to cause discharge in the inner gaps of the porous body placed between the both electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating the entire surface of a non-conductive porous body. According to the present invention, for example, imparting hydrophilicity, hydrophobicity, or adhesion to the entire surface of the nonconductive porous body, improving hydrophilicity, hydrophobicity, or adhesion, or The entire surface of the porous body can be roughened.

[0002]

2. Description of the Related Art Conventionally, as a method for treating a surface of a nonconductive porous body by electric discharge, for example, a method using an AC corona discharge or a DC corona discharge, a method using a low-pressure glow discharge, and the like have been known. . However, when the method using AC corona discharge or DC corona discharge, or the method using low-pressure glow discharge is used, for example, an object to be processed made of synthetic fiber can be subjected to a hydrophilic treatment, but obtained. The effect of hydrophilicity is not long-lasting, and there is a disadvantage that the effect of hydrophilicity is easily reduced by heat treatment or the like.

[0003] As a treatment method capable of imparting hydrophilicity with durability, Japanese Patent Application Laid-Open No. 56-157737 discloses a method of impregnating a hydrophobic resin porous structure with a water-soluble polymer or a surfactant. Discloses a method for producing a durable hydrophilized porous structure by fixing a water-soluble polymer or a surfactant by low-pressure glow discharge. In Japanese Patent Publication No. 13352/1991, a polyethylene glycol aqueous solution is applied to a polyester fiber and dried to give polyethylene glycol, and then a low-pressure glow discharge treatment is performed to fix the polyethylene glycol to the polyester fiber. A method for producing a durable hydrophilic polyester fiber is disclosed.

However, the low-pressure glow discharge requires a pressure reducing device for reducing the pressure in the discharge vessel, and is not suitable for continuous machining. Further, when the object to be treated and / or the water-soluble polymer or the surfactant contains a volatile substance, for example, water or a plasticizer, it is difficult to control the pressure, and the water-soluble polymer or the surfactant is uniformly dispersed. It is difficult to fix to If instead of low pressure glow discharge,
Even if corona discharge performed at atmospheric pressure is used, in corona discharge, a certain or more electric field strength between the discharge electrode and the counter electrode, that is, a high Since it is necessary to apply a voltage,
If the voltage is set too high, spark discharge occurs between the electrodes through a weak part (for example, a thin part) of the object to be processed,
In some cases, damage such as making a large hole in the object to be processed may occur. Also, when processing an object having irregularities,
It is not possible to discharge uniformly, which may cause unevenness in processing or damages such as holes in the object to be processed.

Japanese Patent Application Laid-Open No. 8-337675 discloses that a high frequency / high voltage is applied to a pair of electrodes in a chamber in which a reaction gas is introduced (atmospheric pressure or higher) while a porous body is interposed between the pair of electrodes. Is applied to generate a plasma on the surface of the porous body and the internal space of each hole, thereby modifying the porous body. In this reforming treatment method, hydrophilicity or lipophilicity can be added using the reaction gas, and an organic compound which is liquid or gas at normal temperature and an inert gas (for example, helium, argon, or neon) can be added. And the like, the reforming treatment of the porous body can be performed. But,
In this method, an inert gas such as helium must be used, and it is necessary to perform the operation in a closed system. Therefore, there is a disadvantage in that the operation steps and the structure of the apparatus are complicated, and moreover, an expensive inert gas is used. There is a disadvantage that the cost is high because of the necessity.

[0006]

Therefore, the object of the present invention can be carried out at atmospheric pressure, and the object to be processed due to spark discharge or the like or the processing unevenness hardly occurs.
It is an object of the present invention to provide a method for treating the entire surface of a non-conductive porous body, which can be continuously treated and can perform surface modification with excellent durability.

[0007]

The object of the present invention is to provide a method of the present invention, in which a dielectric layer is provided on each of the opposing surfaces, and a surface modification aid is applied between a pair of electrodes arranged opposite to each other. The non-conductive porous body supported on the treated surface is arranged so that each of the derivative layers does not directly contact with the pair of electrodes, but each of the derivative layers directly contacts the outer surface, and the frequency is 0.1 kHz. Applying a low-frequency AC voltage of about 100 KHz between the two electrodes to generate a discharge in an internal space of the non-conductive porous body sandwiched between the two electrodes; This can be achieved by a method of treating the total surface of the body.

In the present specification, the “total surface” is a concept including both the outer surface of the non-conductive porous body to be treated and the inner surface of the non-conductive porous body. The “outer surface” refers to the surface of the non-conductive porous body in contact with a virtual solid having a smooth surface circumscribing the non-conductive porous body. The “inner surface” means the entire surface of all the internal voids included in the virtual solid of the non-conductive porous body. Therefore, the inner surface is the surface of each cell in the foam-type porous body, and the surface of the concave structure (for example, a hollow or a groove) or the surface of the through-hole in the film-type porous body, The surface of the internal porous body formed by the constituent fibers in the quality-type porous body, that is, the entire surface of each constituent fiber is included.

In the present specification, "treatment of the total surface" means that at least a part of the total surface of the non-conductive porous material to be treated is chemically or physically treated. Chemical treatment means chemically modifying the entire surface of the non-conductive porous body, for example, a treatment for introducing a desired functional group into a compound constituting the non-conductive porous body. To impart hydrophilicity, hydrophobicity, or adhesiveness to the entire surface of the non-conductive porous body, or improve hydrophilicity, hydrophobicity, or adhesiveness. In the presence of a surface modification aid capable of introducing a desired functional group, a discharge is generated in an internal void included in the virtual solid of the non-conductive porous body, whereby the desired functional group is obtained. Can be performed.

[0010] The physical treatment means physically modifying the entire surface of the non-conductive porous body, and examples thereof include roughening by plasma treatment. Rough surface processing can be performed by generating electric discharge in a surface treatment gas such as air. In the method of the present invention, when a chemical treatment is performed, a physical treatment usually occurs simultaneously.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As a non-conductive porous body whose entire surface can be treated by the method of the present invention, a porous body made of any non-conductive organic or inorganic material can be used. According to the method of the present invention, regardless of whether the non-conductive porous body is an organic material or an inorganic material, the non-conductive porous body can be treated, and in particular, a non-conductive porous material made of an organic material which is easily damaged by spark discharge or the like. Even porous porous bodies can be treated. Examples of the non-conductive organic material include various organic polymer compounds, for example, polyolefin such as polyethylene and polypropylene, polyester, polycarbonate, polyvinyl chloride, fluorinated ethylene propylene copolymer (FEP), polyvinylidene fluoride (PVD)
F) or vinylidene fluoride-trifluoroethylene copolymer. Non-conductive inorganic materials include various ceramics (eg, alumina, silica,
Or silica alumina, etc.) or glasses (for example,
Soda glass or silica glass).

As the porous body made of the above-mentioned various materials,
For example, a fibrous porous body, a film porous body, or a foam porous body can be used. The fibrous porous body is made of, for example, a woven fabric, a knitted fabric, a fibrous porous film, or a nonwoven fabric. As the nonwoven fabric, for example, a dry nonwoven fabric (eg, a spunbonded nonwoven fabric, a meltblown nonwoven fabric, a needle punched nonwoven fabric, a binder-bonded nonwoven fabric,
Heat-fused nonwoven fabric or hydroentangled nonwoven fabric) or wet nonwoven fabric. Also, as a foam,
For example, an open-cell foam made of a polyolefin-based, polyester-based, or polyurethane-based resin can be used. Examples of the film-type porous body include a film having an uneven structure and a perforated film.

The present invention is particularly applicable to the treatment of a fibrous porous body made of a non-conductive organic material. For example, a non-woven fabric sheet (eg, a separator for an alkaline battery, a base cloth for a patch material, Or, it can be applied to the treatment of a nonwoven fabric sheet which can be used as a humidifying base material. Non-woven fabrics that can be used as the alkaline battery separator include, but are not limited to, for example, polyolefin fibers, i.e., polyethylene, ethylene copolymer, polypropylene, propylene copolymer, polybutene, A fiber comprising one or more butene-based copolymers, polymethylpentene, or a pentene-based copolymer as a resin component, for example, formed by hydroentanglement, heat fusion, or meltblowing, or a combination thereof. Non-woven fabrics can be used.

The shape of the non-conductive porous body whose entire surface can be treated by the method of the present invention is such that when the outer surface of the non-conductive porous body comes into contact with the dielectric layer, the inside of the porous body is formed. The shape is not particularly limited as long as it has a void. The porosity (porosity in the state at the time of treatment) of the non-conductive porous body whose entire surface can be treated by the method of the present invention is higher than 0% and less than 99%. In particular, the inner surface of the non-conductive porous body having a porosity of 95% or less is difficult to treat by the conventional glow discharge, but can be treated by the present invention.

The upper limit of the size of the internal void is not particularly limited, but preferably the average pore diameter of the void is 1 mm or less. In particular, the inner surface of the non-conductive porous body having an average pore diameter of 0.1 mm or less, particularly 30 μm or less, was difficult to be treated by the conventional glow discharge. Can be. The average pore diameter of the fibrous porous body can be measured, for example, with a Coulter Porometer II (manufactured by Coulter).
If the average pore diameter exceeds 1 mm, arc discharge may occur and damage the porous body. However, even if the average pore diameter exceeds 1 mm, any material can be used as long as it can be compressed during processing to reduce the average pore diameter to 1 mm or less. When the average pore diameter is 0.1 mm or less, sparks are unlikely to occur. The lower limit of the size of the internal void is not particularly limited as long as a discharge can be generated in the internal void of the non-conductive porous body.

The preferred thickness of the non-conductive porous body (thickness between the two dielectric layers) also varies depending on the thickness of the dielectric layer, the type of the porous body, and the like. Although not particularly limited, it is preferably 10 mm or less, more preferably 1 mm or less. 10mm
This is because, when the temperature exceeds the limit, arc discharge easily occurs, and a high discharge voltage is required. When the thickness is 1 mm or less, sparks are less likely to occur, and processing is possible even with materials that are weak to heat. In addition, even if the thickness of the non-conductive porous body exceeds 10 mm, it is compressed during processing to reduce the thickness to 1 mm.
What is necessary is just to be able to be 0 mm or less. Further, the inner surface of the non-conductive porous body having a thickness of 0.1 mm or more has been difficult to treat by the conventional glow discharge, but can be treated by using the present invention. The air permeability of the non-conductive porous body is not particularly limited. Air permeability of 0.5 to 200 ml / cm ²
Seconds, in particular, the inner surface of the non-conductive porous body of 1 to 150 ml / cm ² · sec has been difficult to treat by the conventional glow discharge, but is treated by using the present invention. be able to.

Non-conductive porous material having a porosity of 95% or less, non-conductive porous material having an average internal pore diameter of 0.1 mm or less, non-conductive porous material having a thickness of 0.1 to 10 mm The inner surface of a body (including a body which is compressed to fall within this range) or a non-conductive porous body having an air permeability of 0.5 to 200 ml / cm ² · sec may be treated by glow discharge. However, when the present invention is used, each of the above-mentioned non-conductive porous bodies (particularly, a non-conductive porous body that satisfies all the conditions, that is, the porosity, the internal porosity, The entire surface of the non-conductive porous body whose average pore diameter, thickness, and air permeability are within the above ranges can be treated.

In the method of the present invention, (1) a step of supporting a surface-modifying auxiliary agent on the surface to be treated of the non-conductive porous body (hereinafter, referred to as a pre-treatment step) is performed, and then (2) A) an AC voltage is applied between the non-conductive porous bodies supporting the surface-modifying aid in a state where the non-conductive porous bodies are appropriately arranged between a pair of opposed electrodes, and the porous body sandwiched between the two electrodes is applied; By performing a step of generating discharge in the internal voids of the body (hereinafter, referred to as a discharge treatment step), the entire surface of the non-conductive porous body can be treated.

In the pretreatment step in the method of the present invention, the surface of the nonconductive porous body to be treated, that is, at least the surface of the nonconductive porous body to be subjected to the surface treatment, A surface modification aid is carried. For example, a surface modification aid can be carried on both the outer surface and the inner surface of the non-conductive porous body.

The surface-modifying auxiliary which can be used in the pretreatment step in the method of the present invention, is carried on the surface of the non-conductive porous body by performing the discharge treatment step, whereby the non-conductive There is no particular limitation as long as it can introduce a functional group into the porous body, and it can be appropriately selected according to the purpose of the surface treatment. When imparting hydrophilicity and / or adhesiveness to the non-conductive porous body or performing a surface treatment for improving hydrophilicity and / or adhesiveness, for example, a water-soluble polymer or a surfactant is used. be able to. When imparting hydrophobicity to the nonconductive porous body or performing a surface treatment for improving hydrophobicity, for example, a silicone-based water repellent or a fluorine-based water-repellent can be used.

Examples of the water-soluble polymer include a polymer containing an oxygen atom or a nitrogen atom in the molecule. As a polymer containing an oxygen atom in the molecule,
For example, a polymer containing a functional group such as a hydroxyl group, a carboxyl group, an ether group, a sulfonyl group, or a phosphonyl group can be given. Examples of the polymer containing a nitrogen atom in the molecule include an amino group, an imino group, and an acid amide. Group,
Alternatively, a polymer containing a quaternary ammonium type functional group can be used. Specific examples of the water-soluble polymer include polyethylene glycol, polypropylene glycol, polyvinyl alcohol, poly (meth) acrylic acid, poly (meth) acrylamide, polyethylene oxide, polyethylene imine, polyvinyl pyridine, polyvinyl pyrrolidone, and polystyrene sulfonic acid. And polystyrene ammonium salt.
Examples of the surfactant include a hydrocarbon-based, silicone-based, and fluorine-based surfactant.

In the pretreatment step in the method of the present invention, the surface modification aid can be carried on the surface of the non-conductive porous body by an appropriate method according to the surface modification aid to be used. For example, a surface modification aid is dissolved or suspended in a suitable solvent, and the solution or suspension is impregnated with the non-conductive porous body, or the solution or suspension is mixed with the non-conductive porous body. After spraying or coating on the surface to be treated, the solvent alone is removed, so that the surface modification aid can be carried on the surface to be treated of the non-conductive porous body.

Water-soluble polymers and / or
Alternatively, when a surfactant is used, for example, after impregnating the non-conductive porous body with the aqueous solution of the water-soluble polymer and / or the surfactant, and evaporating water, the surface-modifying auxiliary agent is used. The non-conductive porous body can be supported on the surface to be processed. When a highly hydrophobic material such as polysulfone, polypropylene, polyethylene, or polytetrafluoroethylene is used as the non-conductive porous body, the surface tension is small and can be mixed with water. The surface to be treated of the non-conductive porous body is pre-wetted using a suitable organic solvent and then washed with water and then immersed in an aqueous solution of a water-soluble polymer and / or a surfactant, or subjected to a preliminary discharge treatment. After performing, it is preferable to immerse in an aqueous solution of a water-soluble polymer and / or a surfactant. The preliminary discharge treatment improves the affinity between the surface of the non-conductive porous body to be treated and the aqueous solution of the water-soluble polymer and / or the surfactant, and increases the affinity of the water-soluble polymer and / or the interface. The discharge treatment is not particularly limited as long as the discharge treatment can uniformly adhere the activator, but, for example, in that the treatment can be uniformly performed up to the inside of the non-conductive porous body,
It is preferable to carry out under the same conditions as the discharge treatment carried out in the later-described discharge treatment step.

When a silicone-based water repellent and / or a fluorine-based water repellent is used as a surface modification aid, for example, the water-repellent is dispersed in a volatile organic solvent, and a non-conductive material is dispersed therein. It is preferable to immerse the porous body and then evaporate the organic solvent because the water repellent is uniformly attached.

The discharge treatment step in the method of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows the basic principle of the discharge treatment step in the method of the present invention. As shown in FIG. 1, a pair of electrodes 21 and
2 are arranged to face each other. The electrode 21 carries a dielectric layer 41 that is in surface contact with the facing surface side, and the electrode 22 also
A dielectric layer 42 that is in surface contact with the facing surface side is carried.
Furthermore, the surface between the dielectric layer 41 and the dielectric layer 42 is placed so that the outer surface does not come into contact with either of the electrodes 21 and 22 but the dielectric layer 41 and the dielectric layer 42 come into direct contact with each other. A non-conductive porous body 11 supporting a reforming aid is arranged. At this time, by pressing the electrode 21 and the electrode 22 with an appropriate pressure, the electrode 21 and the dielectric layer 41 are pressed.
A surface is formed so that substantially no space is formed between the dielectric layer 41 and the non-conductive porous body 11, between the non-conductive porous body 11 and the dielectric layer 42, and between the dielectric layer 42 and the electrode 22. Make contact. It is preferable that the size of the electrode 21 and the electrode 22 be smaller than the size of the dielectric layer 41 and the dielectric layer 42 that are in contact with each other, because no spark occurs between the ends of the electrodes 21 and 22. Further, the size of the electrode 21 or the electrode 22 is determined by the dielectric layer
1 or the same size as the dielectric layer 42, by providing a covering material (for example, vinyl tape) made of a dielectric material around the electrodes to prevent sparks between the ends of the electrodes 21 and 22. be able to. The electrode 21 is connected to an AC power supply 51, and the electrode 22 is grounded.

When an AC high voltage is applied from the AC power supply 51, discharge occurs in the internal gap of the non-conductive porous body 11, and plasma is generated. The plasma generated in the internal voids of the non-conductive porous body 11 acts on the inner surface of the non-conductive porous body 11, so that the inner surface of the non-conductive porous body 11 and the surface modification auxiliary are separated. The reaction causes the modification of the inner surface of the non-conductive porous body 11, that is, the introduction of a desired functional group. At this time, since the outer surface of the non-conductive porous body 11 is in contact with the dielectric layer 41 or the dielectric layer 42, the plasma generated in the internal void of the non-conductive porous body 11
Theoretically, it does not act on the contact point of the outer surface of the non-conductive porous body 11 with the derivative layer. However, in practice, the point of contact is a very small area compared to the area of the outer surface, so it can be said that substantially all of the outer surface has been treated. In addition, since the non-conductive porous body is treated not only by plasma but also by radicals generated by the plasma, when the porous body and the dielectric layer are separated from each other, the contact point is generated by radicals remaining without being deactivated. Is also processed. In the present invention, since the discharge is generated in the internal gap of the non-conductive porous body, the non-conductive porous body is hardly damaged by spark discharge or the like.

In the discharge treatment step in the method of the present invention, the lower limit of the AC voltage applied to generate a discharge by an AC power supply depends on the distance between the electrodes including the dielectric layer and the type of gas, and is therefore particularly limited. However, it is preferably 0.25 KVp or more, more preferably 0.5 KVp or more (KVp indicates a voltage difference from the maximum peak of the AC voltage to 0). Voltage is 0.25K
This is because when the voltage is lower than Vp, substantially no discharge occurs. The upper limit of the AC voltage is not particularly limited as long as the voltage does not cause damage to the non-conductive porous body.

Although the upper limit of the frequency of the AC voltage is not particularly limited, it is preferably 100 KHz, more preferably 50 KHz. If the frequency exceeds 100 KHz, the dielectric conductive heating may cause the nonconductive porous body to be overheated and be broken. Further, when the frequency is 50 KHz or less, it is more preferable that the dielectric and the electrode are hardly heated, so that the treatment can be stably performed for a long time. The lower limit of the frequency is preferably 0.1 KHz, more preferably 0.5 KHz,
More preferably, it is 1 KHz. Frequency is 0.1KHz
If it is less than the above, the processing efficiency due to the discharge may decrease. It is more preferable that the frequency be 1 KHz or more, since the processing efficiency is high and the processing time is short.

The output of the AC is not particularly limited since it depends on the shape of each electrode or the material or thickness of the dielectric layer or the non-conductive porous material to be used.
When a pair of electrodes is processed by sandwiching a non-conductive porous body in a certain region (for example, see FIG. 1 or FIG. 4 described later), it is preferably 0.5 to ⁵ W / cm ² . In the case where the pair of electrodes is processed by sandwiching the non-conductive porous body in a linear manner (for example, see FIG. 2, FIG. 3, FIG. 5, or FIG. 6 described later), the output of the AC is: 0.1-9W / cm
And more preferably 0.1 to 6 W / cm. In the case where the non-conductive porous body is linearly sandwiched and processed, and a plurality of electrodes are used (for example, see FIG. 3, FIG. 5, or FIG. 6 described later), The range of the AC output means a value per electrode.

In the discharge treatment step of the method of the present invention, when the output of the alternating current is lower than the above range (that is, when the non-conductive porous body is interposed between certain regions, the output is less than 0.5 W / cm ² ). Or, when the non-conductive porous body is linearly sandwiched and treated, when the discharge is less than 0.1 W / cm), the discharge mainly occurs in a place where the non-conductive porous body is easily discharged. Therefore, it may not be possible to uniformly treat the entire surface. Further, when the AC output is higher than the above range (that is, when the non-conductive porous body is interposed in a certain region and the processing is performed, it exceeds 5 W / cm ² ,
Alternatively, when the non-conductive porous body is processed while being sandwiched in a linear manner and exceeds 9 W / cm), holes may be formed in the non-conductive porous body due to arc discharge.

The waveform of the applied voltage is not particularly limited, and may be, for example, a sine wave, a triangular wave, or a rectangular wave. A pulse wave (for example, (A pulse wave shown in FIG. 10). In the pulse wave, the rise time of the voltage wave (for example, time t in FIG. 10) is 1
The time is preferably not more than microsecond, more preferably not more than 0.5 microsecond. Further, the voltage pulse width (half width) (for example, the width w in FIG. 10) is preferably 10 μs or less, more preferably 2 μs or less. The preferred range of the frequency when using the pulse wave (for example, the frequency when one cycle of the wavelength λ in FIG. 10) is not limited, but the upper limit is preferably set for the same reason as described above. Is 100 KHz, more preferably 50 KHz, and the lower limit thereof is preferably 0.1 KHz, more preferably 0.5 KHz, and still more preferably 1 KHz. By using such a pulse wave, the entire surface treatment can be performed without making a hole even in a non-conductive porous material (for example, a melt-blown nonwoven fabric) in which holes are easily formed by spark discharge. Note that these values relating to the alternating current applied to generate a discharge largely deviate from the above-mentioned range because they greatly depend on the shape of each electrode, the material of the non-conductive porous body, the discharge voltage waveform, and the processing time. Sometimes used.

FIG. 1 shows an embodiment in which an AC power supply 51 is connected to the electrode 21 and the electrode 22 is grounded. However, in the discharge treatment step in the method of the present invention, the AC power supply 51 is connected to the electrode 22. Alternatively, the electrode 21 may be grounded.

The electrode material that can be used in the electric discharge treatment step in the method of the present invention has a specific resistance of preferably 10 ³ Ω · cm or less, more preferably 10 ⁰ Ω · cm.
The following conductors can be used. For example, a metal (for example, stainless steel, aluminum, tungsten, or the like), a conductive metal oxide, carbon, or a conductor (for example, metal powder or carbon powder) and rubber Conductive rubber or the like can be used. As the shape of the electrode, for example, a sheet electrode, a plate electrode, or a columnar electrode can be used. As in the embodiments shown in FIGS. 2 to 6 described below, when the non-conductive porous body and the electrode relatively move, so that it is difficult to damage the surface of the non-conductive porous body, A columnar electrode that is capable of rotating itself around the central axis of the column in synchronization with the parallel movement of the nonconductive porous body is preferable.

In the discharge treatment step in the method of the present invention, the lower limit of the pressure applied between the two electrodes ensures the surface contact between the electrode and the dielectric layer and between the dielectric layer and the non-conductive porous body. Pressure that does not substantially form a space. The upper limit is a pressure that does not destroy the shape of the non-conductive porous body.

The dielectric layer which can be used in the electric discharge treatment step in the method of the present invention may be entirely non-porous, or may include a porous portion in a part thereof. If a dielectric layer composed entirely of a porous portion is used as the dielectric layer, spark discharge may be generated inside the nonconductive porous body and the porous portion of the dielectric. Therefore, in the present invention, it is not preferable to use such a dielectric layer. For the same reason, it is not preferable to use a dielectric layer including a porous portion continuous in the thickness direction as the dielectric layer. When a dielectric layer having a porous portion is used on the contact surface with the non-conductive porous body, the use of the dielectric layer and the non-conductive porous Since the contact surface with the body is reduced, the outer surface of the non-conductive porous body can be treated more efficiently.

The material of the dielectric layer that can be used in the electric discharge treatment step in the method of the present invention includes, for example, glass, ceramic (eg, alumina), rubber (eg, synthetic rubber, eg, silicone rubber, chloroprene rubber, Or a butadiene rubber or a natural rubber), or a thermoplastic resin (for example, polytetrafluoroethylene or polyester).
It is preferable to use a rubber or a thermoplastic resin for the dielectric layer in contact with the non-conductive porous body, especially for the contact surface because of its excellent elasticity. It is more preferable to use rubber because it has excellent adhesion to the body. In particular, it is preferable to use rubber that does not easily damage the surface of the non-conductive porous body, or polytetrafluoroethylene that is resistant to dielectric breakdown. The thickness of the dielectric layer is not particularly limited, but may be 0.05 to 5 m.
m is preferable. If it is thicker than 5 mm, a very high voltage is required to discharge, and 0.05 mm
If the amount is less than the above, the mechanical strength is reduced, and dielectric breakdown is likely to occur.

When the dielectric layer used in the electric discharge treatment step in the method of the present invention includes a porous portion in a part thereof, the thickness of the porous dielectric portion, the thickness of the entire dielectric layer and the thickness of the object to be processed are determined. The thickness of the porous dielectric portion and the object to be processed (that is, the non-conductive porous body) are 10 mm, although the preferred thickness varies depending on the type of the material. The following is preferred. 10m
If m exceeds m, arc discharge is likely to occur and a high discharge voltage is required. The upper limit of the height of the internal voids in the porous dielectric portion is not particularly limited, but the average void height in the thickness direction is 500
It is preferable that the gap is not more than μm. If the average gap height exceeds 500 μm, an arc discharge may occur and the workpiece may be damaged. However, even if the average gap height exceeds 500 μm, any material can be used as long as the average gap height can be reduced to 500 μm or less by compression during processing. The lower limit of the height of the internal void is not particularly limited as long as a discharge can be generated in the internal void of the porous dielectric portion.

In the discharge treatment step in the method of the present invention, when imparting hydrophilicity or improving the hydrophilicity, the treatment is generally carried out in an open system (in air). Alternatively, when improving hydrophobicity,
It is preferable that the non-conductive porous body and its vicinity are filled with a specific gas so that contact with air does not occur and an undesired reaction does not occur. When the surroundings of the non-conductive porous body are set to the atmosphere of the specific gas, for example, the non-conductive porous body, the electrode, and the dielectric layer are arranged in an airtight container, and the specific With gas filled,
Discharge treatment can also be performed. In this case, the processing region can be filled with a specific gas, and no contact with air occurs, which is preferable. As the specific gas, for example, an inert gas having no reactivity, for example, helium or argon can be used.

According to the method of the present invention, the non-conductive porous body is substantially treated only on the entire surface of the portion sandwiched between the pair of electrodes, so that the shape of at least one of the electrodes is adjusted. The shape of the region to be processed can be arbitrarily adjusted. For example, one of the electrodes is a plate-like electrode, the other electrode of a desired shape, such as a reticulated electrode or a linear electrode, by the same pattern as the desired shape, for example, a reticulated pattern or a linear pattern The non-conductive porous body can be selectively treated.

The discharge treatment step in the method of the present invention is not limited to the embodiment shown in FIG. 1 in which a discharge is generated in a state where the non-conductive porous material carrying the surface modification aid is stationary, The surface treatment of the non-conductive porous body can be continuously performed while moving the non-conductive porous body carrying the auxiliary agent. FIG. 2 shows another embodiment of such a discharge treatment step in the method of the present invention.

In this embodiment, the columnar electrode 21 and the columnar electrode 22 are arranged to face each other. The surfaces of the electrodes 21 and 22 are the dielectric layers 41 and 42.
Each is covered. The electrode 21 and the electrode 22 may be capable of rotating themselves with the column central axis as a rotation axis, or may be fixed without rotating. When the non-conductive porous body moves, it is an electrode that can rotate itself around the center axis of the cylinder in that the surface of the non-conductive porous body is not easily scratched. preferable.

The electrode 21 is connected to an AC power supply 51 and the electrode 2
Ground 2 The non-conductive porous body 11 carrying the surface modification aid is transferred to the surfaces of the electrodes 21 and 22 by a transfer means (for example, a pair of delivery rollers: not shown) provided upstream of the electrodes 21 and 22. It is continuously supplied at a predetermined speed in the direction shown by arrow A between the dielectric layers 41 and 42 carried thereon, and passes between the dielectric layers 41 and 42 while contacting them. I do. The non-conductive porous body 11 having passed between the two dielectric layers 41 and 42 is moved at a predetermined speed by a transfer means (for example, a pair of delivery rollers: not shown) provided downstream of the two electrodes 21 and 22. Transferred continuously. A driving means (for example, a motor) for supplying a driving force for transporting the non-conductive porous body 11 can be connected to the above-mentioned delivery roller and / or a rotatable electrode.

The supply speed and the transfer speed of the non-conductive porous body 11 are not particularly limited, and may be a constant speed or a speed that changes periodically or irregularly.
These speeds are preferably constant so that the surface treatment time of the non-conductive porous body becomes 0.1 seconds or more. If the speed is higher than this, a sufficient total surface treatment effect may not be obtained.

When an AC high voltage is applied from an AC power supply 51 when the non-conductive porous body 11 carrying the surface modification aid passes between the dielectric layers 41 and 42 while contacting them. The discharge is generated in the internal space of the non-conductive porous body 11 sandwiched between the contact surfaces of the dielectric layers 41 and 42 and the non-conductive porous body 11, and plasma is generated. . The inner surface of the non-conductive porous body 11 reacts with the surface modification aid by the action of the plasma generated in the internal voids of the non-conductive porous body 11, and the non-conductive porous body 11
Is modified, that is, a desired functional group is introduced. At this time, the plasma generated in the internal gap of the non-conductive porous body 11 does not act on the contact surface between each of the dielectric layers 41 and 42 and the non-conductive porous body 11. However, since the non-conductive porous body 11 is continuously transferred at a predetermined speed, the outer surface of the non-conductive porous body 11, which was the contact surface, is separated from the dielectric layer 41 and the dielectric layer 42. The outer surface of the non-conductive porous body 11 is reformed by the action of the plasma generated in the internal space in the vicinity immediately after separation.

Since the non-conductive porous body 11 is continuously transferred at a predetermined speed, the untreated non-conductive porous body 11
Is continuously supplied between the two dielectric layers 41 and 42, while the non-conductive porous body 11 whose entire surface is modified is continuously supplied between the two dielectric layers 41 and 42. Thus, the total surface treatment of the non-conductive porous body 11 can be performed continuously.

Also in the embodiment shown in FIG. 2, the AC voltage applied to generate a discharge by the AC power supply is not particularly limited, but for the same reason as described in the embodiment shown in FIG. It is preferable that they are in the same range as the AC voltage and the frequency. In the embodiment shown in FIG. 2, the AC power supply 51 is connected to the electrode 21 and the electrode 22 is grounded. On the contrary, the AC power supply 51 may be connected to the electrode 22 and the electrode 21 may be grounded. . In the embodiment shown in FIG. 2 as well, when imparting hydrophilicity or improving hydrophilicity is generally carried out in an open system (in air), hydrophobicity is imparted or hydrophobicity is increased. In order to improve the non-conductive porous body, the non-conductive porous body and its vicinity are filled with a specific gas (for example, an inert gas such as helium or argon) so that contact with air does not occur, Preferably, no reaction occurs.

In the embodiment shown in FIG. 2, only one columnar electrode 21 carrying a dielectric layer 41 is provided on the surface thereof, but the number of electrodes 21 is not particularly limited, and one electrode 21 is provided. Or a plurality can be provided. A plurality of electrodes carrying a dielectric layer may be provided so that any one point on the outer surface of the non-conductive porous body can make multiple contact with the dielectric layer carried on the surface of the electrode. This is preferable in that the processing effect can be enhanced and the processing speed can be increased.

Five small-diameter cylindrical electrodes carrying a dielectric layer on its surface are arranged in parallel at predetermined intervals along the surface of the dielectric layer carried on the large-diameter cylindrical electrode surface. FIG. 3 shows still another embodiment of the electric discharge treatment step in the method of the present invention, which is arranged in FIG. 5 cylindrical electrodes 21
(21a, 2 from the upstream side in the flow direction of the non-conductive porous body)
1b, 21c, 21d, and 21e) at predetermined intervals along the surface of the dielectric layer 42 carried on the surface of the cylindrical electrode 22 having a larger diameter than those electrodes. And five electrodes 21a-21
e and the electrode 22 are arranged so as to face each other. The five electrodes 21a to 21e are respectively connected to the dielectric layers 41a to 41e.
(Hereinafter, may be collectively referred to as a dielectric layer 41).

The electrode 21 and the electrode 22 may be such that they can rotate themselves with the column central axis as a rotation axis, or may be fixed without rotating, and may be non-conductive. When the porous body 11 and the electrode 21 and the electrode 22 move relatively, the surface of the non-conductive porous body is hardly damaged, and therefore, rotates itself around the center axis of the cylinder. It is preferable that the electrode be capable of being used.

The five electrodes 21a to 21e are connected to one common AC power supply 51, and the electrode 22 is grounded. In addition,
When the electrodes 21a to 21e are connected to the same AC power supply, each electrode can be arranged so that a certain electrode is in contact with an adjacent electrode. In the mode shown in FIG. 3, the five electrodes 21a to 21e are connected to one common AC power supply 51, and the same AC high voltage is applied to all of the five electrodes 21a to 21e. Different AC high voltages may be applied to the electrodes by connecting different electrodes to different AC power supplies. However, when different electrodes are connected to different AC power supplies, they need to be sufficiently separated so that the electrodes do not contact each other.

The non-conductive porous body 11 carrying the surface-modifying aid is transported by the transfer means (for example, a pair of delivery rollers 81a and 81b) provided upstream of the electrode 21 and the electrode 22. Between the dielectric layer 41 and the dielectric layer 42 respectively carried on the surface of the electrode 22 at a predetermined speed in the direction shown by the arrow A, with one surface carried on the surface of the electrode 22. 5 layers of dielectric material 41 in continuous contact with layer 42 and at the same time the opposite surface.
a, 41b, 41c, 41d, and 41e, and sequentially passes between the dielectric layers 41e and 42 while being in contact with the dielectric layers 41e and 41e.
The non-conductive porous body 11 that has passed between the dielectric layer 41 and the dielectric layer 42 is transferred to a transfer unit (for example, a pair of delivery rollers 82a, 82a) provided downstream of the electrodes 21 and 22.
According to b), it is continuously transferred at a predetermined speed. A driving means (for example, a motor) for supplying a driving force for transporting the non-conductive porous body 11 can be connected to the above-mentioned delivery roller and / or a rotatable electrode.

The supply speed and the transfer speed of the non-conductive porous body 11 are not particularly limited, and may be a constant speed or a speed that changes periodically or irregularly.
In the embodiment shown in FIG. 3, it is preferable that the speed is constant and the speed is such that the total surface treatment time of the non-conductive porous body is 0.1 second or more. If the speed is higher than this, a sufficient total surface treatment effect cannot be obtained.

Also in the embodiment shown in FIG. 3, when the nonconductive porous body 11 carrying the surface modifying aid passes between the dielectric layer 41 and the dielectric layer 42 while contacting them. When an AC high voltage is applied from an AC power supply 51, the inside of the non-conductive porous body 11 sandwiched between the contact surfaces of the dielectric layers 41 and 42 and the non-conductive porous body 11, respectively. Discharge occurs in the gap, and plasma is generated. As described in the embodiment shown in FIG. 2, the inner surface and the outer surface of the non-conductive porous body 11 are modified by the action of the plasma generated in the voids inside the non-conductive porous body 11.

In the embodiment shown in FIG. 3, the non-conductive porous body 1
Five electrodes 21a to 21e are provided so that any one point on the outer surface of one can contact the dielectric layer carried on the surface of the electrode a plurality of times. Five electrodes 21a-
21e, the surface of each of the dielectric layers 41a-41
e. Therefore, the non-conductive porous body 11 whose entire surface has been modified by the dielectric layer 41a carried on the surface of the electrode 21a and the dielectric layer 42 is transported in the direction shown by the arrow A, and The dielectric layer 41b is supplied between the dielectric layer 41b carried on the surface of the dielectric layer 21b and the dielectric layer 42, and the entire surface is reformed again by the dielectric layer 41b and the dielectric layer 42. 41c, the dielectric layer 41d, and the dielectric layer 41e are sequentially supplied, the entire surface is modified, and supplied from between the dielectric layer 41e and the dielectric layer 42.

Since the non-conductive porous body 11 is continuously transferred at a predetermined speed, the untreated non-conductive porous body 11
Is continuously supplied between the dielectric layer 41a and the dielectric layer 42, and the non-conductive porous body 11 whose surface has been modified is placed between the dielectric layer 41e and the dielectric layer 42. , And the total surface treatment of the non-conductive porous body 11 can be continuously performed.

The embodiment shown in FIG. 3 can be implemented in an open system or a closed system as in the embodiment shown in FIG. When imparting hydrophilicity or when improving hydrophilicity,
Generally, it is carried out in an open system (in the air). However, when imparting hydrophobicity or improving hydrophobicity, the nonconductive porous body and its vicinity are filled with a specific gas (for example, helium or helium). (Inert gas such as argon), so that contact with air does not occur and undesired reactions do not occur.

A method according to the present invention using a belt-like laminate of an electrode layer and a dielectric layer, for example, a belt-like aluminum vapor-deposited film, instead of the five sets of electrodes 21a to 21e and dielectric layers 41a to 41e shown in FIG. FIG. 4 shows still another embodiment of the discharge treatment step. Four fixed rollers 91
a, 91b, 91c, and 91d are arranged so that the axial directions are parallel to each other, and the four fixed rollers are positioned at the vertices of the rectangle when viewed from the axial direction. The fixed roller 91a is provided near the dielectric layer 42, and the fixed roller 91b is provided downstream of the fixed roller 91a and close to the dielectric layer 42. The two fixed rollers 91c and 91d are arranged apart from the dielectric layer 42.

The endless belt-shaped aluminum vapor-deposited film 31 having the aluminum layer 23 formed by vapor-depositing aluminum on one surface of the polyester dielectric film layer 43 was fixed to four fixed rollers 9.
It arrange | positions so that it may pass outside 1a, 91b, 91c, 91d. At this time, the aluminum layer 23 of the aluminum vapor-deposited film 31 is placed inside (that is, so as to be able to contact the four fixing rollers 91a, 91b, 91c, 91d), and the polyester dielectric film layer 43 is placed outside. (That is, the fixed roller 91
a and the polyester dielectric film layer 4 of the aluminum vapor-deposited film 31 passing between the fixed roller 91b and the fixed roller 91b
3 and a dielectric layer 4 carried on the surface of the cylindrical electrode 22
2 so as to face each other).

On the other hand, the electrode 22 having the dielectric layer 42 on its surface is fixed from the fixed roller 91a to the fixed roller 91a.
The endless belt-shaped aluminum vapor-deposited film 31 and the dielectric layer 42 are arranged so as to be in continuous surface contact in the entire region up to b. In this embodiment, it is not always necessary to make surface contact in the entire area between the fixed roller 91a and the fixed roller 91b, and by adjusting the distance between the endless belt-shaped aluminum vapor-deposited film 31 and the electrode 22, the fixed roller It is sufficient that at least a part of the region between the fixing roller 91b and the fixing roller 91b is in contact with the dielectric layer 42.

The electrode 22 itself can rotate around its cylindrical central axis as a rotation axis. Also, the four fixed rollers 91a, 91b, 91c, 91d can also rotate themselves around the column central axis as a rotation axis.
1 can move in one direction (for example, the direction indicated by arrow B). The aluminum layer 23 of the aluminum deposition film 31 is connected to an AC power supply 51, and the electrode 22 is grounded. The embodiment shown in FIG. 4 connects an AC power supply 51 to the aluminum layer 23 and grounds the electrode 22.
Conversely, an AC power supply 51 may be connected to the electrode 22 and the aluminum vapor-deposited film 31 may be grounded.

The non-conductive porous body 11 carrying the surface-modifying aid is transported by a transfer means (for example, a pair of delivery rollers 81a, 8a) provided upstream of the fixed roller 91a and the electrode 22.
1b), it is continuously supplied at a predetermined speed in the direction shown by arrow A between the dielectric layer 42 carried on the surface of the electrode 22 and the fixed roller 91a, and one surface is
2. While continuously contacting the dielectric layer 42 carried on the substrate 2 and at the same time continuously contacting the surface opposite thereto with the polyester dielectric film layer 43, the gap between the dielectric layer 42 and the fixing roller 91b is maintained. pass. The non-conductive porous body 11 that has passed between the dielectric layer 42 and the fixed roller 91b is
It is continuously transferred at a predetermined speed by a transfer means (for example, a pair of sending rollers 82a and 82b) provided downstream of the fixed roller 91b and the electrode 22. Driving means for supplying a driving force for transferring the non-conductive porous body 11 (for example,
Motor), the fixed roller, the delivery roller and / or
Alternatively, it can be connected to a rotatable electrode.

In the embodiment shown in FIG. 4, the total surface treatment of the non-conductive porous body 11 can be continuously performed in the same manner as in the embodiment shown in FIG. The embodiment shown in FIG. 4 has a larger discharge area than the embodiment shown in FIG. 3, so that the processing effect can be enhanced and the processing speed can be increased. Also, in the embodiment shown in FIG. 4, similarly to the embodiment shown in FIG. 3, it can be implemented in an open system or a closed system. In addition, as a belt-shaped laminate of an electrode layer and a dielectric layer that can be used in the embodiment shown in FIG. 4, in addition to the belt-shaped aluminum vapor-deposited film, the electrode of the belt-shaped laminate is, for example, a metal foil. , A metal sheet, or a conductive resin sheet containing a conductive substance, and the like. Examples of the dielectric material of the belt-shaped laminate include a resin film, a resin sheet, and a rubber sheet. They can be appropriately laminated and used. Naturally, a metal vapor deposition film other than aluminum can also be used.

FIG. 5 shows still another embodiment of the discharge treatment step in the method of the present invention using a flat electrode 22 and a dielectric carrier 44a as a set of electrodes and a dielectric layer. A pair of carrier driving rollers 9 arranged at a predetermined interval
2a and 92b, a dielectric carrier 44a made of a dielectric capable of transporting the non-conductive porous body 11 in a fixed direction (the direction indicated by arrow A), and the dielectric carrier 44a
Five cylindrical electrodes 21 (21a, 21b, 21c, 21d, and 2d from the upstream side in the flow direction of the non-conductive porous body 11) arranged in parallel at predetermined intervals along the surface of
1e) may be disposed to face each other. The five electrodes 21a to 21e are respectively covered with dielectric layers 41a to 41e (hereinafter, may be collectively referred to as dielectric layer 41).

The electrode 21 may be one that can rotate itself around the central axis of the cylinder, or one that is fixed without rotation, and may be a nonconductive porous material. When the electrode and the electrode move relative to each other, the surface of the non-conductive porous body is less likely to be damaged, so that the electrode itself can rotate around the center axis of the cylinder as a rotation axis. preferable. For the dielectric carrier 44a,
An electrode 22 made of a plate-like electrode or the like is arranged on the opposite side of the electrode 21 so as to face the electrode 21.

The five electrodes 21a to 21e are connected to one common AC power supply 51, and the electrode 22 is grounded. The mode shown in FIG. 5 connects five electrodes 21a to 21e to one common AC power supply 51 and applies the same AC high voltage to all five electrodes 21a to 21e. By connecting different electrodes to different AC power supplies, different AC high voltages can also be applied to each electrode. Also,
In the embodiment shown in FIG. 5, a common AC power supply 51 is connected to the five electrodes 21a to 21e and the electrode 22 is grounded. Conversely, an AC power supply is connected to the electrode 22 and the five electrodes 21a to 21e are connected to the ground. 21a to 21e may be grounded.

The non-conductive porous body 11 carrying the surface-modifying aid is transferred onto the dielectric carrier 44a by a transfer means (eg, a pair of delivery rollers 81a, 81b) provided upstream of the electrodes 21 and 22. And is continuously supplied at a predetermined speed between the electrode 21a and the electrode 22 by the dielectric carrier 44a in the direction shown by the arrow A, and one surface thereof is always in contact with the dielectric carrier 44a, and at the same time, On the opposite surface, five dielectrics 41a, 41b, 41c, 41
The electrode 21e and the electrode 22 are sequentially contacted with d and 41e.
Pass between. The non-conductive porous body 11 that has passed between the electrode 21e and the electrode 22 is transferred on the dielectric carrier 44a, and is provided on a transfer means (for example, a pair of delivery rollers 82a) provided downstream of the electrode 21 and the electrode 22. , 82b) are continuously transferred at a predetermined speed. Driving means for supplying a driving force for transferring the non-conductive porous body 11 (for example,
Motor) can be connected to the carrier drive roller, the delivery roller, and / or the rotatable electrode.

In the embodiment shown in FIG. 5, the total surface treatment of the non-conductive porous body 11 can be continuously performed in the same manner as in the embodiment shown in FIG. In this embodiment, by using the dielectric carrier, a normal flat electrode can be used as the inducing electrode. The embodiment shown in FIG.
In the same manner as in the embodiment shown in FIG. In the embodiment shown in FIG. 5, as a combination of an electrode and a dielectric layer, a combination of a plate-shaped electrode 22 and a dielectric carrier 44a, five sets of electrodes 21a to 21e and a dielectric layer 41a
Although the combination of No. to 41e is used, a belt-like laminate of an electrode layer and a dielectric layer shown in FIG. 4 can be used instead of one or both of them.

FIG. 6 shows an embodiment in which a belt-like laminate of an electrode layer and a dielectric layer is used instead of the combination of the flat electrode 22 and the dielectric carrier 44a shown in FIG. In the embodiment shown in FIG. 6, a three-layer laminate including a polyester dielectric film layer 44, an aluminum layer 23, and a carrier 43 is used. The three-layer laminate can be prepared by laminating an aluminum vapor-deposited film composed of the aluminum layer 23 and the polyester dielectric film layer 44 and the carrier 43. This polyester dielectric film layer 44 is brought into contact with the aluminum layer 23 on one side and simultaneously with the non-conductive porous body 11. In this embodiment, a two-layer laminate composed of the aluminum layer 23 and the polyester dielectric film layer 44 can be used, but the carrier 43 can improve the durability of the aluminum layer 23 as an electrode layer. .

As the dielectric layer, the entire surface of the dielectric layer facing the non-conductive porous body is a dielectric layer composed of a porous dielectric layer, that is, the porous layer on the surface side facing the non-conductive porous body. FIG. 7 shows another embodiment of the discharge treatment step in the method of the present invention using a dielectric layer composed of a porous dielectric layer and a non-porous dielectric layer on the electrode side. As shown in FIG. 7, a pair of electrodes 21 and 22 composed of a plate-like electrode or the like are arranged to face each other. The electrode 21, which is the first electrode, carries a dielectric layer 45 on the opposing surface side thereof. The dielectric layer 45 includes a non-porous dielectric layer 46 on the electrode 21 side and a porous dielectric layer 46 on the opposing surface side. Layer 4
7 The electrode 22, which is the second electrode, carries a non-porous dielectric layer 42 on the opposing surface side.

The porous dielectric layer 47 and the non-porous dielectric layer 47 are not in contact with either of the electrodes 21 and 22, but are in contact with the porous dielectric layer 47 and the non-porous dielectric layer 42 so that the outer surfaces thereof are in direct contact with each other. The non-conductive porous body 11 supporting the surface modification aid is disposed between the non-conductive porous body 11 and the porous dielectric layer 42. At this time, the porous dielectric layer 47 and the non-conductive porous body 11 are pressed by pressing the electrode 21 and the electrode 22 with an appropriate pressure.
And between the non-conductive porous body 11 and the non-porous dielectric layer 42 so that substantially no space (gap) is formed. When a space is formed between the dielectric layer and the non-conductive porous body, discharge does not occur uniformly,
Holes may be formed in the non-conductive porous body. One electrode,
For example, the electrode 21 is connected to an AC power supply 51, and the other electrode, for example, the electrode 22 is grounded. An AC power supply 51 may be connected to the electrode 22 and the other electrode 21 may be grounded.

When an AC high voltage is applied from the AC power supply 51, discharge occurs not only in the internal voids of the non-conductive porous body 11 as the object to be processed but also in the internal voids of the porous dielectric layer 47, and plasma is generated. Is done. The plasma generated in the internal space of the non-conductive porous body 11 acts on the inner surface and the outer surface of the non-conductive porous body, and the plasma generated in the internal space of the porous dielectric layer 47 is also non-conductive. Acts on the inner surface and the outer surface of the conductive porous body to modify the entire surface of the non-conductive porous body 11. At this time, a portion of the outer surface of the non-conductive porous body 11 which is in contact with the porous dielectric layer 47 is theoretically formed by plasma generated in the internal void of the porous dielectric layer 47. , Not modified. However, in practice, the point of contact is a very small area compared to the area of the outer surface, so it can be said that substantially all of the outer surface has been treated.

In the discharge treatment step in the method of the present invention, both of the dielectric layers can be replaced with a dielectric layer including a porous dielectric portion on at least a part of the surface on the facing surface side. Also, in the embodiments shown in FIGS. 2 to 6, one or both of the dielectric layers can be replaced with a dielectric layer including a porous dielectric portion on at least a part of its opposing surface side surface.

[0073]

EXAMPLES The present invention will be described below in more detail with reference to examples, but these examples do not limit the scope of the present invention. Example 1: General table using aqueous polyethylene glycol solution
As the surface-treated object, a polypropylene / polyethylene split fiber is wet-processed, then the split fiber is split by a hydroentanglement treatment, and the entangled nonwoven fabric (width = 180 m)
m, length = 350 mm, thickness = 0.3 mm, porosity = 8
0%, average pore size = 9 μm, air permeability = 15.3 ml / cm
² seconds). The discharge treatment was performed using an apparatus similar to the apparatus shown in FIG. That is, the flat stainless steel electrodes 21 and 22 (width = 150 mm, length = 3
00 mm) on the dielectric layer 4 made of a Teflon sheet.
1, 42 (width 180 mm, length = 350 mm, thickness =
0.1 mm). The nonwoven fabric is sandwiched between the dielectric layers 41 and 42, and an alternating current of 800 W (frequency = 12.5 KH) is applied to the electrodes 21 and 22 from the impulse power supply 51.
z, voltage = 3 KVp, current = 130 mA) was applied for 1 minute to perform a discharge treatment in the air (hereinafter, sometimes referred to as a preliminary discharge treatment). 8% polyethylene glycol (molecular weight = 1000)
It was immersed in an aqueous solution. Pull up the nonwoven fabric from the aqueous solution,
The nonwoven fabric was squeezed with an appropriate force so that a polyethylene glycol aqueous solution three times the weight of the nonwoven fabric before the treatment was attached, and then dried at 60 ° C. After performing the discharge treatment again under the same conditions as the preliminary discharge treatment, the washing treatment of the nonwoven fabric (washing with warm water at 60 ° C. for 30 minutes) was repeated twice, and the weight of the obtained nonwoven fabric was measured. 6
% Increased.

Example 2: Ethanol of polyethylene glycol
It is not performed on the total surface treatment preliminary discharge treatment using Nord solution, and except for using an ethanol solution of 8% 8% polyethylene glycol in place of polyethylene glycol solution, repeating the same operation as in Example 1 Was.

Example 3: Polypropylene glycol aqueous solution
The same operation as in Example 1 was repeated, except that an 8% aqueous solution of polypropylene glycol (molecular weight = 400) was used instead of the 8% aqueous solution of polyethylene glycol subjected to the total surface treatment using the liquid .

Example 4: Evaluation of durability against hot water treatment The nonwoven fabric obtained in the above Examples 1 to 3, ie, the nonwoven fabric treated by the method of the present invention and the nonwoven fabric not subjected to the total surface treatment (control) were used. Immersed in hot water at 100 ° C. for 1 hour, cut into 2.5 cm width, and cut one end (1 cm from one end) of the cut long sample into water for 1 minute. Was measured. Table 1 shows the results after performing the hot water treatment together with the results before performing the hot water treatment. The hydrophilic effect of the nonwoven fabric obtained by the method of the present invention was maintained even by heat treatment immersed in hot water.

[0077]

[Table 1] Nonwoven fabric After hot water treatment Before hot water treatment Nonwoven fabric obtained in Example 1 5.3 cm 5.0 cm Nonwoven fabric obtained in Example 2 4.8 cm 4.8 cm Nonwoven fabric obtained in Example 3 0.9cm 5.8cm Control non-woven fabric 0cm 0cm

Example 5: Evaluation of durability against dry heat treatment The nonwoven fabrics obtained in Examples 1 to 3 were subjected to dry heat treatment at 100 ° C for 1 hour, and then cut into a width of 2.5 cm. One end (1 cm from one end) of the sample was immersed in water for 1 minute, and the water absorption height was measured. Table 2 shows the results after performing the dry heat treatment together with the results before performing the dry heat treatment. The nonwoven fabric obtained by the method of the present invention maintained its hydrophilic effect even by dry heat treatment.

[0079]

Table 2 Nonwoven fabric After hot water treatment Before hot water treatment Nonwoven fabric obtained in Example 1 5.1 cm 5.0 cm Nonwoven fabric obtained in Example 2 4.4 cm 4.8 cm Nonwoven fabric obtained in Example 3 5.8cm 5.8cm control non-woven fabric 0cm 0cm

Example 6 Evaluation of Battery Life As the separator for an alkaline battery, the nonwoven fabric sheet obtained in the above Example 1 was filled with nickel hydroxide in a foamed nickel support as a positive electrode, and a hydrogen storage alloy was used as a negative electrode. (Mesh metal MmNi ₅ type) filled in a foamed nickel support, and then 7.2N as an electrolytic solution
Cylindrical paste-paste sealed nickel-metal hydride batteries (battery capacity = 1750 mAh) were prepared using 5 g of potassium hydroxide / 1.0 N aqueous lithium hydroxide solution. The nonwoven fabric obtained in Example 1 used as a separator had good electrolyte absorbability and excellent workability in battery production. In a 20 ° C constant temperature bath, replace the battery with 5
A charge / discharge operation consisting of charging at 90 mAh for 4 hours (0.3 C, 120% of theoretical capacity) and discharging at 590 mAh until the final voltage reaches 1 V is defined as one cycle.
The charge / discharge for battery activation was performed for 5 cycles. Using a battery that has been subjected to 5 cycles of charge / discharge for battery activation, the battery was charged at 1750 mAh for 1.5 hours in a thermostat at 20 ° C. (1.0 C,
A life test was performed in which a charge / discharge operation consisting of discharging at 1750 mAh until the end voltage reached 0.8 V as one cycle was performed (150% of the theoretical capacity).

FIG. 8 shows the battery discharge capacity after each cycle.
FIG. 9 shows the average charging voltage in each cycle. As is clear from FIG. 8, no decrease in the discharge capacity was observed even after 450 cycles of the charge / discharge operation.
Further, as is apparent from FIG. 9, it is considered that the rise in the charging voltage was small, and therefore the rise in the internal resistance was small (that is, the liquid drainage of the separator was small). By using the nonwoven fabric treated by the method of the present invention as a separator, a battery having a long cycle life can be manufactured.

[0082]

According to the method of the present invention, the entire surface of the non-conductive porous body can be surface-modified with excellent durability. In addition, according to the method of the present invention, the total surface treatment can be performed at atmospheric pressure, and the object to be treated due to spark discharge or the like is less likely to be damaged or unevenness in the treatment. Can be performed. Furthermore, according to the method of the present invention, the non-conductive porous body is substantially treated only on the entire surface of the portion sandwiched between the pair of electrodes, so that one of the electrodes is a plate-like electrode, When the other is an electrode having a desired shape, for example, a mesh electrode or a linear electrode, the surface of the object to be processed can be selectively processed into the same pattern as the desired shape. The present invention can be applied to the treatment of a fibrous porous body made of a non-conductive organic material, particularly an alkaline battery separator,
The present invention can be applied to the treatment of a nonwoven fabric sheet which can be used as a base material for a patch material or a humidifying substrate.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a basic principle of a discharge treatment step in a method of the present invention.

FIG. 2 is a perspective view schematically showing one embodiment of a discharge treatment step in the method of the present invention.

FIG. 3 is a cross-sectional view schematically showing another embodiment of the discharge treatment step in the method of the present invention.

FIG. 4 is a cross-sectional view schematically showing still another embodiment of the discharge treatment step in the method of the present invention.

FIG. 5 is a cross-sectional view schematically showing still another embodiment of the discharge treatment step in the method of the present invention.

FIG. 6 is a cross-sectional view schematically showing still another embodiment of the discharge treatment step in the method of the present invention.

FIG. 7 is a cross-sectional view schematically showing still another embodiment of the electric discharge treatment step in the method of the present invention.

FIG. 8 is a graph showing a cycle change of battery discharge capacity in a life test of a nickel-metal hydride battery using an alkaline battery separator manufactured by the method of the present invention.

FIG. 9 is a graph showing a cycle change of a charging average voltage in a life test of a nickel-metal hydride battery using an alkaline battery separator manufactured by the method of the present invention.

FIG. 10 is an explanatory diagram showing the shape of a pulse wave that can be used in the method of the present invention.

[Explanation of symbols]

11. non-conductive porous body; 21, 22, electrodes 23
..Aluminum layer; 31.aluminum vapor-deposited film; 41,42..non-porous dielectric layer; 43..carrier; 44..polyester dielectric film layer; 44a
..Dielectric carrier; 45. Dielectric layer; 46. Non-porous dielectric layer; 47. Porous dielectric layer; 51 .. AC power supply; 81a, 81b, 82a, 82b. 91a, 91b, 91c, 91d, fixed rollers; 92a, 92b, rollers.

Claims (1)

[Claims] 1. A non-conductive porous body carrying a surface-modifying auxiliary agent on a surface to be treated is provided between a pair of electrodes provided with a dielectric layer on each of the opposed surfaces and opposed to each other. The pair of electrodes are not directly in contact with each other, but are arranged such that each of the derivative layers and the outer surface are in direct contact with each other,
A low-frequency AC voltage having a frequency of 0.1 KHz to 100 KHz is applied between the two electrodes to generate a discharge in an internal space of the non-conductive porous body sandwiched between the two electrodes. And a method for treating the entire surface of the non-conductive porous body.